1. Field of the Invention
The present invention concerns prefabricated electrical trunking of the kind made up by butt-jointing unit enclosure sections each housing a unit conductor assembly comprising parallel electrical conductors.
2. Discussion of the Background
For fastening the envelope sections together, this type of trunking incorporates mechanical coupling usually comprising flanges adapted to cover the ends of the sections near the plane of the joint, the flanges being adapted to be clamped against the enclosure and/or to each other by screws or bolts passing through the enclosure walls.
It is essential to improve the quality of sealing in the coupling region to protect the electrical conductors and the members interconnecting them from the risk of ingress of water. From this point of view the fact that the bolts of the coupling pass through the trunking enclosure constitutes a problem.